#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>

#include <stddef.h> 
//modifier fixed  alignment number  
//offsetof is a fonction to calculate the type shall be a structure or union type. 
struct Book
{
	char name[20];
	int page;
	char writer[20];
};

//if I wanna change the alignment number 
# pragma pack(1)
int main()
{
	printf("%d\n", sizeof(struct Book));
	printf("%d\n",(int) offsetof(struct Book,page));
	printf("%d\n", (int)offsetof(struct Book,name));
	printf("%d\n", (int)offsetof(struct Book,writer));

}